| Acronym | Definition |
|---|
| NSEC | Network Switching Engineering Center |
| NSEC | Nano Second |
| NSEC | Nanoscale Science and Engineering Center (Cambridge, MA) |
| NSEC | Norwegian Seafood Export Council (est. 1991; Norway) |
| NSEC | National Security Engineering Center (US DoD) |
| NSEC | North-South Economic Corridor (transport route; Asian Development Bank) |
| NSEC | National Safety Education Center (Northern Illinois University) |
| NSEC | National Solar Energy Centre (Commonwealth Scientific and Industrial Research Organisation; Newcastle, New South Wales, Australia) |
| NSEC | National System for Emergency Coordination (US EPA) |